In the following code, I just want to connect to hbase and do a get operation
in a mapper.
Any insight on this?
Thanks,
Lei
public class TagMapper extends Mapper<LongWritable, Text, Text, Text> {
private HTable hTable;
@Override
protected void setup(Context context){
try {
hTable = new HTable(context.getConfiguration(), "userdigest");
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String agid = value.toString();
Get get = new Get(Bytes.toBytes(agid));
Result rs = hTable.get(get);
for(KeyValue kv:rs.raw()){
context.write(new Text(new String(kv.getRow())+":" + new
String(kv.getQualifier())), new Text(new String(kv.getValue())));
}
}
}
The task error log:
java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at
sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:599)
at
org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:350)
at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1068)
2014-08-15 17:43:11,102 WARN
org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: Possibly transient
ZooKeeper exception:
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode =
ConnectionLoss for /hbase/hbaseid
2014-08-15 17:43:11,103 INFO org.apache.zookeeper.ClientCnxn: Opening socket
connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate
using SASL (Unable to locate a login configuration)
2014-08-15 17:43:11,103 ERROR
org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: ZooKeeper exists failed
after 3 retries
2014-08-15 17:43:11,103 WARN org.apache.hadoop.hbase.zookeeper.ZKUtil:
hconnection Unable to set watcher on znode (/hbase/hbaseid)
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode =
ConnectionLoss for /hbase/hbaseid
at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
at org.apache.zookeeper.ZooKeeper.exists(ZooKeeper.java:1041)
at
org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.exists(RecoverableZooKeeper.java:172)
at org.apache.hadoop.hbase.zookeeper.ZKUtil.checkExists(ZKUtil.java:450)
at
org.apache.hadoop.hbase.zookeeper.ClusterId.readClusterIdZNode(ClusterId.java:61)
at org.apache.hadoop.hbase.zookeeper.ClusterId.getId(ClusterId.java:50)
at org.apache.hadoop.hbase.zookeeper.ClusterId.hasId(ClusterId.java:44)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.ensureZookeeperTrackers(HConnectionManager.java:615)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:871)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:846)
at org.apache.hadoop.hbase.client.HTable.finishSetup(HTable.java:271)
at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:211)
at org.apache.hadoop.hbase.client.HTable.<init>(HTable.java:170)
at
com.agrantsem.data.mapreduce.userdigest.TagMapper.setup(TagMapper.java:23)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:138)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:672)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:330)
at org.apache.hadoop.mapred.Child$4.run(Child.java:268)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1408)
at org.apache.hadoop.mapred.Child.main(Child.java:262)
2014-08-15 17:43:11,103 WARN org.apache.zookeeper.ClientCnxn: Session 0x0 for
server null, unexpected error, closing socket connection and attempting
reconnect
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